Radiotherapy for localized prostate carcinoma. The correlation of pretreatment prostate specific antigen and nadir prostate specific antigen with outcome as assessed by systematic biopsy and serum prostate specific antigen

The history of cryosurgery in Canada: A tale of two cities

Although not commonly available in Canada, cryosurgery (cryoablation) for prostate cancer has been practiced in many countries. The field of cryoablation has evolved significantly over the past 30 years. Two prostate cryoablation programs were started in Canada in the early 1990s, in London, ON and Calgary, AB, focusing, respectively, on salvage therapy following radiation failure and primary local treatment. This article chronicles the development of the two programs and outlines the scientific and clinical contributions by investigators at the two centers.

Radical dose escalation by high-dose-rate brachytherapy for localized prostate cancer-Significance of prostate-specific antigen nadir level within 18 months as correlation for long-term biochemical control

PURPOSE

High-dose-rate brachytherapy (HDR-BT) for dose escalation in localized prostate cancer has been established as one standard treatment option. However, long-term results at followup (FU) ≥5 years are usually needed to ensure robustness of reported outcomes. Potential benefit of salvage therapy is, nevertheless, higher when relapse is diagnosed early. This study aimed to solve this dilemma by evaluating the prostate-specific antigen (PSA) nadir for early prediction of long-term biochemical control.

METHODS AND MATERIALS

Combined pelvis-external beam radiation/HDR-BT boost to EQD2 >100 Gy (α/β = 3) was performed in 459 consecutively treated patients. These patients with an FU ≥ 24 months were analyzed and stratified in PSA nadir (nPSA)-groups by PSA nadir within 18 months after radiotherapy (nPSA18). Kaplan-Meier/log-rank tests and Cox-regression models were used to compare the study endpoints.

RESULTS

The mean FU was 77 months. A PSA nadir within 18 months (nPSA18) <0.5 ng/mL was achieved in 222 patients with median time to reach nPSA18 of 7 months. The 5-year American Society of Therapeutic Radiology and Oncology (ASTRO) biochemical control (prostate-specific antigen disease-free survival) for the nPSA18 group <0.5 ng/mL was 89% and for the group ≥ 0.5 ng/mL, it was 78.6% (p = 0.011). nPSA18 was an independent predictor of cancer-specific survival, distant metastasis-free survival, and biochemical control (ASTRO) (p = 0.026, p = 0.020, and p = 0.01, respectively).

CONCLUSIONS

The present results suggest that the PSA nadir level within 18 months after radiotherapy may serve as an early parameter for long-term biochemical control according to ASTRO definitions following radical dose escalation by HDR-BT for prostate cancer. Excellent outcomes were associated with nPSA18 < 0.5 ng/mL.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Treatment effects in prostate cancer

Nonsurgical treatments for prostate cancer include androgen-deprivation therapy (ADT), radiation therapy (RT), ablative therapies, chemotherapy, and newly emerging immunotherapies. These approaches can be used alone or in combination depending on the clinical scenario. ADT is typically reserved for high-risk locally or systemically advanced disease that is not amenable to curative surgery. Radiation therapy can be used instead of surgery as primary therapy with curative intent for low-intermediate-risk disease as well as for control of locally advanced disease not suitable for surgery. Ablative therapies can be used as primary therapy for low-intermediate-risk disease or as salvage therapy for clinically localized disease where RT has failed. Chemotherapy and immune-based therapies are currently used for androgen-independent disease, although the indications for these approaches may well change as new data from clinical trials accrue. Pathologists should be able to recognize tissue changes associated with these treatments to provide information that will optimize patient management. This is particularly true in situations where clinical history of recent or remote nonsurgical treatment is not provided with the specimen. In the absence of this information, pathologists encountering the features described herein are encouraged to review patient records or communicate directly with clinical colleagues to determine how a given patient was treated and when.

Does prostate-specific antigen nadir predict longer-term outcomes of prostate cancer after neoadjuvant and adjuvant androgen deprivation therapy in conjunction with brachytherapy?

PURPOSE

To evaluate whether nadir prostate-specific antigen (nPSA), time to nPSA (TnPSA), and nPSA 3-years post-treatment are prognostic for prostate cancer (PC) in patients treated with temporary brachytherapy plus external beam radiation therapy (EBRT) and hormonal manipulation.

METHODS AND MATERIALS

We retrospectively analyzed our database of 253 patients with Stage T1-T3 N0M0 PC who underwent brachytherapy with temporary brachytherapy plus EBRT. All patients received neoadjuvant androgen deprivation for a median of 6 months. Treatment consisted of three pulses of pseudo pulsed-dose-rate brachytherapy to a median dose of 18Gy with 50.4Gy in 28 fractions of EBRT. Treatment took place between December 1999 and March 2006.

RESULTS

At a median of 6-years followup, nPSA value was a predictor of biochemical control. Rising nPSA categories of <0.01, 0.01-<0.05, 0.05-≤0.1, 0.1-≤ 1.0, or >1.0 ng/mL correlated with a deteriorating 5-year biochemical control (nBED) by the Phoenix definition of 100%, 90.0%, 82.5%, 64.3%, and 10%, respectively. A highly statistically significant relationship between nPSA value and subsequent clinical failure is also demonstrated. The relationship between TnPSA and nBED was strongly significant (p<0.0001), with a significantly longer nPSA for patients who had Phoenix nBED. A PSA of <1.5 ng/mL achieved 3-year post radiation therapy was prognostic for biochemical and clinical disease control (p<0.0001).

CONCLUSION

The nPSA, TnPSA, and reaching a PSA cutoff level of <1.5 ng/mL at 3 years post-treatment can provide useful prognostic information on long-term biochemical and clinical control of PC in patients treated with pseudo PDR, EBRT, and hormone manipulation.

Current approaches, challenges and future directions for monitoring treatment response in prostate cancer

Prostate cancer is the most commonly diagnosed non-cutaneous neoplasm in men in the United States and the second leading cause of cancer mortality. One in 7 men will be diagnosed with prostate cancer during their lifetime. As a result, monitoring treatment response is of vital importance. The cornerstone of current approaches in monitoring treatment response remains the prostate-specific antigen (PSA). However, with the limitations of PSA come challenges in our ability to monitor treatment success. Defining PSA response is different depending on the individual treatment rendered potentially making it difficult for those not trained in urologic oncology to understand. Furthermore, standard treatment response criteria do not apply to prostate cancer further complicating the issue of treatment response. Historically, prostate cancer has been difficult to image and no single modality has been consistently relied upon to measure treatment response. However, with newer imaging modalities and advances in our understanding and utilization of specific biomarkers, the future for monitoring treatment response in prostate cancer looks bright.

PSA Doubling Time Predicts for the Development of Distant Metastases for Patients Who Fail 3DCRT Or IMRT Using the Phoenix Definition

PURPOSE: PSA doubling time (PSADT) is commonly used as an indication for salvage androgen deprivation therapy (ADT) for PSA failure following RT. Previously, we had shown that PSADT of <12 months is an important predictor of distant metastasis following 3DCRT using the ASTRO definition of BF. We sought to determine if this approach is still valid using the Phoenix definition. METHODS: Eligible patients included 432 men with T1-3N0M0 prostate cancer who demonstrated PSA failure after completing definitive 3DCRT or IMRT from 1989-2005. Endpoints included freedom from distant metastasis (FDM), cause-specific survival (CSS) and overall survival (OS). PSADT was stratified by 0-6, 6-12, 12-18, 18-24, and >24 months. The median follow-up was 95 months (6-207 months). RESULTS: The 7 year FDM, CSS, and OS rates for the entire group were 73%, 77% and 52%, respectively. 7 year FDM was 50% for PSADT <6 months vs. 83% for PSADT >6 months (p=0.0001). 7 year CSS was 61% for PSADT <6 and 85% for PSADT >6 (p=0.0001). 7 year OS was 47% for PSADT <6 and 53% for PSADT >6 (p=0.04). The proportion of men with BF receiving salvage ADT with a PSADT <6 months was 59%, 6-12 was 45%, 12-18 was 42%, 18-24 was 36%, >24 was 28%. ADT was associated with improved 7 year CSS (68% vs. 46%, p=0.015). Of the 314 men with PSADT >6 months, 124 received ADT and 190 were observed. With a median follow-up of 38 months from BF, there was no demonstrable benefit to ADT in the 7 year CSS (87% vs. 79%, respectively; p=0.758). Independent predictors of FDM were PSADT (p<0.0001), GS (p=0.011), and the use of initial ADT (p=0.005). CONCLUSION: PSADT remains a significant predictor of clinical failure and CSS for men treated with 3DCRT or IMRT who fail according to the Phoenix definition. Immediate use of ADT in patients with PSADT <6 months is significantly associated with improved CSS, although the benefit is less apparent in patients with longer PSADT. These results further refine the role of PSADT in predicting which patients may benefit from salvage ADT and those who may be observed expectantly.

Postradiotherapy 2-year prostate-specific antigen nadir as a predictor of long-term prostate cancer mortality

PURPOSE

To report the influence of posttreatment prostate-specific antigen (PSA) nadir response at 2 years after external beam radiotherapy (RT) on distant metastases (DM) and cause-specific mortality (CSM).

METHODS AND MATERIALS

Eight hundred forty-four patients with localized prostate cancer were treated with conformal RT. The median duration of follow-up was 9.1 years. A fixed landmark time point at 2 years was used to assess the influence of nadir PSA value as a time-dependent variable on long-term outcomes.

RESULTS

Multivariate analysis demonstrated that nadir PSA <or=1.5 ng/mL at the landmark was an independent predictor of progression-free survival after adjusting for T stage, Gleason score, pre-RT PSA value, and RT dose (p = 0.03). The 5- and 10-year cumulative incidences of DM were 2.4% and 7.9%, respectively, in those with nadir PSA levels <or=1.5 ng/mL at the 2-year landmark, and were 10.3% and 17.5%, respectively, in patients with higher nadir values. Multivariate analysis showed that the higher nadir PSA value at the 2-year landmark (p = 0.002), higher Gleason scores (p < 0.001), and increasing T stage (p = 0.03) were predictors of DM after adjusting for pre-RT PSA values and RT dose. Multivariate analysis also showed that higher Gleason scores (p = 0.002), and higher nadir PSA values at the 2-year landmark (p = 0.03) were risk factors associated with CSM after adjusting for T stage and pre-RT PSA value.

CONCLUSIONS

Nadir PSA values of <or=1.5 ng/mL at 2 years after RT for prostate cancer predict for long-term DM and CSM outcomes. Patients with higher absolute nadir levels at 2 years after treatment should be evaluated for the presence of nonresponding disease, and earlier salvage treatment interventions should be considered.

External beam radiotherapy for clinically localized hormone-refractory prostate cancer: clinical significance of Nadir prostate-specific antigen value within 12 months

PURPOSE

To analyze retrospectively the results of external beam radiotherapy for clinically localized hormone-refractory prostate cancer and investigate the clinical significance of nadir prostate-specific antigen (PSA) value within 12 months (nPSA12) as an early estimate of clinical outcomes after radiotherapy.

METHODS AND MATERIALS

Eighty-four patients with localized hormone-refractory prostate cancer treated with external beam radiotherapy were retrospectively reviewed. The total radiation doses ranged from 30 to 76 Gy (median, 66 Gy), and the median follow-up period for all 84 patients was 26.9 months (range, 2.7-77.3 months).

RESULTS

The 3-year actuarial overall survival, progression-free survival (PFS), and local control rates in all 84 patients after radiotherapy were 67%, 61%, and 93%, respectively. Although distant metastases and/or regional lymph node metastases developed in 34 patients (40%) after radiotherapy, local progression was observed in only 5 patients (6%). Of all 84 patients, the median nPSA12 in patients with clinical failure and in patients without clinical failure was 3.1 ng/mL and 0.5 ng/mL, respectively. When dividing patients according to low (<0.5 ng/mL) and high (>or=0.5 ng/mL) nPSA12 levels, the 3-year PFS rate in patients with low nPSA12 and in those with high nPSA12 was 96% and 44%, respectively (p < 0.0001). In univariate analysis, nPSA12 and pretreatment PSA value had a significant impact on PFS, and in multivariate analysis nPSA12 alone was an independent prognostic factor for PFS after radiotherapy.

CONCLUSIONS

External beam radiotherapy had an excellent local control rate for clinically localized hormone-refractory prostate cancer, and nPSA12 was predictive of clinical outcomes after radiotherapy.

Dynamic contrast-enhanced magnetic resonance imaging for localization of recurrent prostate cancer after external beam radiotherapy

PURPOSE

To compare the performance of T2-weighted (T2w) imaging and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the prostate gland in the localization of recurrent prostate cancer in patients with biochemical failure after external beam radiotherapy (EBRT).

METHODS AND MATERIALS

T2-weighted imaging and DCE MRI were performed in 33 patients with suspected relapse after EBRT. Dynamic contrast-enhanced MRI was performed with a temporal resolution of 95 s. Voxels enhancing at 46 s after injection to a greater degree than the mean signal intensity of the prostate at 618 s were considered malignant. Results from MRI were correlated with biopsies from six regions in the peripheral zone (PZ) (base, mid, and apex). The percentage of biopsy core positive for malignancy from each region was correlated with the maximum diameter of the tumor on DCE MRI with a linear regression model.

RESULTS

On a sextant basis, DCE MRI had significantly better sensitivity (72% [21of 29] vs. 38% [11 of 29]), positive predictive value (46% [21 of 46] vs. 24% [11 of 45]) and negative predictive value (95% [144 of 152] vs. 88% [135 of 153] than T2w imaging. Specificities were high for both DCE MRI and T2w imaging (85% [144 of 169] vs. 80% [135 of 169]). There was a linear relationship between tumor diameters on DCE MRI and the percentage of cancer tissue in the corresponding biopsy core (r = 0.9, p < 0.001), with a slope of 1.2.

CONCLUSIONS

Dynamic contrast-enhanced MRI performs better than T2w imaging in the detection and localization of prostate cancer in the peripheral zone after EBRT. This may be helpful in the planning of salvage therapy.

Prostate gland: MR imaging appearance after vascular targeted photodynamic therapy with palladium-bacteriopheophorbide

PURPOSE

To prospectively evaluate the magnetic resonance (MR) imaging appearance of the prostate and periprostatic tissues after vascular targeted photodynamic therapy (VTP) with palladium-bacteriopheophorbide for locally recurrent carcinoma after external beam radiation therapy.

MATERIALS AND METHODS

Informed consent was obtained from all patients, and approval was obtained from the ethics review boards of all participating institutions. Nonenhanced T2-weighted and dynamic gadolinium-enhanced T1-weighted MR imaging examinations were performed at baseline and 1 week, 4 weeks, and 6 months after VTP in 25 men (age range, 58-83 years; mean age, 73 years) as part of a prospective phase I/II trial. Percentage of MR-depicted necrosis was defined as the volume of nonenhancing prostatic tissue 1 week after VTP divided by the volume of the prostate. Patterns of intra- and extraprostatic necrosis were recorded. Pearson correlation coefficients were used to test correlations between necrosis and prostate-specific antigen level.

RESULTS

Contrast material-enhanced T1-weighted MR images obtained 1 week after therapy showed necrosis in all patients. Treatment margins were irregular in 21 of 25 patients. T2-weighted images showed no clear treatment boundaries in any patient. Extraprostatic necrosis involved the puborectalis or levator ani muscles in 22, obturator internus muscle in 12, periprostatic veins in three, pubic bone marrow in four, and anterior rectal wall in nine of the 25 patients. The neurovascular bundle appeared to be spared in all patients. Percentage of MR-depicted intraprostatic necrosis was correlated with percentage decrease in prostate-specific antigen level (from baseline) at 4 weeks (r=0.41, P=.04) and 12 weeks (r=0.45, P=.02).

CONCLUSION

Contrast-enhanced MR imaging depicts irregular margins of intraprostatic treatment effect. This finding suggests varied tissue sensitivities to VTP with palladium-bacteriopheophorbide.

Phase I Trial of Replication-competent Adenovirus-mediated Suicide Gene Therapy Combined with IMRT for Prostate Cancer

Replication-competent adenovirus-mediated suicide gene therapy is an investigational cancer treatment in which an oncolytic adenovirus armed with chemo-radiosensitizing genes is used to destroy tumor cells. Previously, we evaluated the toxicity and efficacy of this approach in two clinical trials of prostate cancer using a first-generation adenovirus. Here, we report the toxicity and preliminary efficacy of this approach in combination with intensity-modulated radiotherapy (IMRT) in patients with newly diagnosed prostate cancer using an improved, second-generation adenovirus. The investigational therapy was associated with low toxicity, and there were no dose-limiting toxicities or treatment-related serious adverse events. Relative to a previous trial using a first-generation adenovirus, there was no increase in hematologic, hepatic, gastrointestinal (GI), or genitourinary (GU) toxicities. Post-treatment prostate biopsies yielded provocative preliminary results. When the results of two similar trials were combined, 22% of evaluable patients were positive for adenocarcinoma at their last biopsy, which is better than expected (>or=40%) for this cohort of patients (P=0.038). When the results were categorized by prognostic risk, most of the treatment effect was observed in the intermediate-risk group, with 0 of 12 patients (0%) being positive for cancer at their last biopsy (P<0.01). These results further demonstrate the safety of this investigational approach and raise the possibility that it may have the potential to improve the outcome of conformal radiotherapy in select patient groups.

Prostate cancer gene therapy clinical trials

Despite recent advances in early detection and treatment, prostate cancer is still the second leading cause of cancer death in men in the United States, and approximately 27,000 men will die from it this year. Better treatments are needed for aggressive forms of localized disease and hormone-refractory metastatic disease. Recently, several gene therapy strategies have generated provocative results in early-stage clinical trials, raising the possibility that gene therapy may have the potential to affect both localized and metastatic disease. Much work lies ahead. Nevertheless, for the time being, these studies provide hope that gene therapy may someday earn a place in the management of prostate cancer.

Prostate-specific antigen nadir within 12 months of prostate cancer radiotherapy predicts metastasis and death

BACKGROUND

The nadir prostate-specific antigen (PSA) at 1 year (nPSA12) was investigated as an early estimate of biochemical and clinical outcome after radiotherapy (RT) alone for localized prostate cancer.METHODS.From May 1989 to November 1999, 1000 men received 3D conformal RT alone (median, 76 Gy) with minimum and median follow-up periods of 26 and 58 months, respectively, from the end of treatment. The calculation of PSA doubling time (PSADT) was possible in 657 patients. Multivariate analyses (MVAs) via Cox proportional hazards regression were used to determine the association of nPSA12 to biochemical failure (BF; ASTRO definition), distant metastasis (DM), cause-specific mortality (CSM), and overall mortality (OM). Dichotomization of nPSA12 was optimized by evaluating the sequential model likelihood ratio and P-values.RESULTS.In MVA, nPSA12 as a continuous variable was independent of RT dose, T-stage, Gleason score, pretreatment initial PSA, age, and PSADT in predicting for BF, DM, CSM, and OM. Dichotomized nPSA12 (2 versus >2 ng/mL) was independently related to DM and CSM. Kaplan-Meier 10-year DM rates for nPSA12 2 versus >2 ng/mL were 4% versus 19% (P<.0001).CONCLUSIONS.nPSA12 is a strong independent predictor of outcome after RT alone for prostate cancer and should be useful in identifying patients at high risk for progression to metastasis and death.

Nadir prostate-specific antigen within 12 months after radiotherapy predicts biochemical and distant failure

OBJECTIVES

To determine whether nadir prostate-specific antigen (PSA) levels within 12 months (nadir PSA12) after completion of radiotherapy (RT) can be used as an early marker of recurrence risk.

METHODS

A total of 4839 patients were treated with RT and without hormonal therapy from 1986 to 1995 for Stage T1-T2 prostate cancer at nine institutions. Of these 4839 patients, 4833, with a median follow-up of 6.3 years, met the criteria for analysis. The study endpoints included freedom from PSA failure, initiation of androgen deprivation, or documented local or distant failure (PSA-DFS); freedom from clinically apparent distant metastasis (DMFS); and overall survival (OS).

RESULTS

Patients with a nadir PSA12 of 2.0 ng/mL or less had an 8-year PSA-DFS, DMFS, and OS rate of 55%, 95%, and 73%, respectively, compared with 40%, 88%, and 69%, respectively, for patients with a nadir PSA12 of more than 2.0 ng/mL. Multivariate analysis confirmed that a nadir PSA12 of greater than 2 ng/mL was an independent predictor of PSA-DFS, DMFS, and OS. Classification and regression tree analysis identified the nadir PSA12 levels after RT associated with PSA-DFS, DMFS, and OS. Nadir PSA12, combined with the pretreatment PSA level, identified patients at particularly high risk of distant metastasis.

CONCLUSIONS

The results of this large, multi-institutional study have demonstrated that nadir PSA12 is predictive of clinical outcomes for patients with localized prostate cancer after RT. A high pretreatment PSA level and high nadir PSA12 will identify patients at particularly high risk who might benefit from early adjuvant therapy.

Prognostic value of PSA nadir ≤4 ng/mL within 4 months of high-dose radiotherapy for locally advanced prostate cancer

PURPOSE

To investigate early prostate-specific antigen (PSA) kinetics after high radiation doses of 85 Gy on locally advanced prostate cancer.

METHODS AND MATERIALS

A total of 201 patients were prospectively and consecutively treated with external beam radiotherapy and a brachytherapy boost. Of the 201 patients, 104 received concomitant hormonal therapy on the decision of the referring urologist and were excluded, yielding a study population of 97 patients. The first posttreatment PSA analysis was performed not earlier than 1 month after treatment completion but within the first 4 months, and then every 4 months. Analysis of PSA kinetics included the PSA nadir (nPSA) at values of < or =4 ng/mL to < or =0.5 ng/mL. The nPSA at < or =4 ng/mL within 4 months (nPSA < or =4/4m) was the variable of interest.

RESULTS

We established highly significant associations between an nPSA of < or =1 and < or =0.5 ng/mL and the nPSA < or =4/4m (p <0.0001). A hazard ratio of 0.33 (95% Confidence Interval (CI), 0.12-0.91) underlined the lower risk of recurrence related to nPSA < or =4/4m achievement (p = 0.033). Using time-dependent covariate models for patients who did not reach an nPSA < or =4/4m, an nPSA of < or =1 ng/mL remained without prognostic significance (p = 0.06). However, for patients who reached an nPSA < or =4/4m, an nPSA of < or =1 ng/mL did significantly improve the prognosis (p <0.001), but much later after treatment. The same analysis was repeated for nPSA < or =0.5 ng/mL with similar conclusions as when nPSA < or =4/4m was obtained (p <0.01).

CONCLUSION

The nPSA < or =4/4m has been demonstrated to be a significant predictor of biochemical no evidence of disease after high radiation doses of 85 Gy. Its major advantage is that it was available earlier than the other nadirs.

Role of Salvage Radical Prostatectomy for Recurrent Prostate Cancer After Radiation Therapy

Patients with isolated local recurrence of prostate cancer after radiation therapy may potentially be cured of their disease by salvage radical prostatectomy (RP). The stage-specific 5-year cancer-control rates of salvage RP resemble those of standard RP. However, the ability to effectively administer salvage treatment to patients with radiorecurrent disease is compromised by the lack of diagnostic tests with sufficient sensitivity and specificity to detect local recurrence at an early stage while it is amenable to local salvage therapy. By the time biochemical recurrence is declared using the current American Society for Therapeutic Radiology and Oncology definition, the majority of patients have advanced local disease, precluding successful local salvage therapy. When salvage RP is performed at prostate-specific antigen levels of 10 ng/mL or less, an estimated 70% of patients are free of disease at 5 years. With better patient selection and technical modifications, the morbidity associated with salvage RP has improved substantially. Rates of urinary incontinence and anastomotic stricture are acceptable, although one third of patients will experience these complications. Salvage cryotherapy is a minimally invasive alternative to salvage RP, but cancer-control rates appear to be inferior and it does not provide a clear advantage over salvage RP in terms of reduced morbidity. Patients with local recurrence after radiation therapy are at increased risk of metastatic progression and cancer-specific mortality. Currently, salvage RP represents the only curative treatment option for these patients. Salvage RP may favorably alter the natural history of biochemical recurrence after radiation therapy, but it must be instituted early in the course of recurrent disease to be effective.

PSA nadir predicts biochemical and distant failures after external beam radiotherapy for prostate cancer: a multi-institutional analysis

PURPOSE

To determine the significance of prostate-specific antigen (PSA) nadir (nPSA) and the time to nPSA (T(nPSA)) in predicting biochemical or clinical disease-free survival (PSA-DFS) and distant metastasis-free survival (DMFS) in patients treated with definitive external beam radiotherapy (RT) for clinical Stage T1b-T2 prostate cancer.

METHODS AND MATERIALS

Nine participating institutions submitted data on 4839 patients treated between 1986 and 1995 for Stage T1b-T2cN0-NxM0 prostate cancer. All patients were treated definitively with RT alone to doses > or =60 Gy, without neoadjuvant or planned adjuvant androgen suppression. A total of 4833 patients with a median follow-up of 6.3 years met the criteria for analysis. Two endpoints were considered: (1) PSA-DFS, defined as freedom from PSA failure (American Society for Therapeutic Radiology and Oncology definition), initiation of androgen suppression after completion of RT, or documented local or distant failure; and (2) DMFS, defined as freedom from clinically apparent distant failure. In patients with failure, nPSA was defined as the lowest PSA measurement before any failure. In patients without failure, nPSA was the lowest PSA measurement during the entire follow-up period. T(nPSA) was calculated from the completion of RT to the nPSA date.

RESULTS

A greater nPSA level and shorter T(nPSA) were associated with decreased PSA-DFS and DMFS in all patients and in all risk categories (low [Stage T1b, T1c, or T2a, Gleason score < or =6, and PSA level < or =10 ng/mL], intermediate [Stage T1b, T1c, or T2a, Gleason score < or =6, and PSA level >10 but < or =20 ng/mL, or Stage T2b or T2c, Gleason score < or =6, and PSA level < or =20 ng/mL, or Gleason score 7 and PSA level < or =20 ng/mL], and high [Gleason score 8-10 or PSA level >20 ng/mL]), regardless of RT dose. The 8-year PSA-DFS and DMFS rate for patients with nPSA <0.5 ng/mL was 75% and 97%; nPSA > or =0.5 but <1.0 ng/mL, 52% and 96%; nPSA > or =1.0 but <2.0 ng/mL, 40% and 91%; and nPSA > or =2.0 ng/mL, 17% and 73%, respectively. The 8-year PSA-DFS and DMFS rate for patients with T(nPSA) <6 months was 27% and 66%; T(nPSA) > or =6 but <12 months, 31% and 85%; T(nPSA) > or =12 but <24 months, 42% and 94%; and T(nPSA) > or =24 months, 75% and 99%, respectively. A shorter T(nPSA) was associated with decreased PSA-DFS and DMFS, regardless of the nPSA. Both nPSA and T(nPSA) were significant predictors of PSA-DFS and DMFS in multivariate models incorporating clinical stage, Gleason score, initial PSA level, and RT dose. The significance of nPSA and T(nPSA) was supported by landmark analysis, as well as by analysis of nPSA and T(nPSA) as time-dependent covariates. A dose > or =70 Gy was associated with a lower nPSA level and longer T(nPSA) in all risk categories, and a greater dose was significantly associated with greater PSA-DFS and DMFS in multivariate analysis. Regression analysis confirmed that higher clinical stage, Gleason score, and initial PSA were associated with a greater nPSA level.

CONCLUSION

The results of this large, multi-institutional analysis of 4833 patients have provided important evidence that nPSA and T(nPSA) after definitive external beam RT are not only predictive of a predominantly PSA endpoint (PSA-DFS), but are also predictive of distant metastasis in all clinical risk categories. Greater RT doses were associated with lower nPSA, longer T(nPSA), and improved PSA-DFS and DMFS.

Recovery of erectile function after salvage radical prostatectomy for locally recurrent prostate cancer after radiotherapy

OBJECTIVES

To analyze the feasibility of neurovascular bundle (NVB) preservation and peripheral nerve grafting during salvage radical prostatectomy (RP) for radiorecurrent prostate cancer and analyze their effect on the recovery of potency.

METHODS

Of 100 patients who underwent salvage RP with curative intent from 1984 to 2003, 7 patients had bilateral NVBs preserved, 22 had a unilateral NVB preserved with (n = 11) and without (n = 11) a unilateral nerve graft, and 9 had bilateral NVBs resected with bilateral nerve grafts. Preoperative erections were graded as normal (grade 1) in 12 patients and full but recently diminished (grade 2) in 16. Recovery of potency after salvage RP was defined as erections satisfactory for intercourse, with or without the use of sildenafil.

RESULTS

Overall, 6 patients recovered potency after salvage RP, and the 5-year actuarial recovery rate was 16% (95% confidence interval 4% to 28%). The 6 patients who recovered erections all had preoperative grade 1 to 2 erections, and 5 had bilateral NVBs preserved. Only 1 of 11 patients who had a unilateral nerve graft recovered potency. No patient with bilateral nerve grafts recovered potency. The 5-year actuarial recovery rate among patients with preoperative grade 1 to 2 erections was 45% (95% confidence interval 16% to 75%).

CONCLUSIONS

Compared with standard RP, the overall potency results after salvage RP are poor. However, select patients with good preoperative erectile function who have bilateral NVB preservation may recover erections sufficient for intercourse aided by sildenafil. Peripheral nerve grafts did not appear to influence the recovery of erections in this patient population.

Local and systemic therapy for patients with metastatic prostate cancer: should the primary tumor be treated?

Data from well-designed, prospective clinical trials are lacking to support treatment of primary tumor in men diagnosed with metastatic prostate cancer. However, a growing body of evidence suggests that treatment of the primary tumor may enhance cancer control and survival in some men. This evidence is examined and recommendations are made for identifying patients with metastatic prostate cancer who may benefit from definitive treatment of the prostate tumor.

LIMITATIONS IN THE USE OF SERUM PROSTATE SPECIFIC ANTIGEN LEVELS TO MONITOR PATIENTS AFTER TREATMENT FOR PROSTATE CANCER

PURPOSE

We reviewed the literature to help clarify the benefits and/or hazards associated with monitoring serum prostate specific antigen (PSA) after treatment with surgery or radiation therapy (RT) for nonmetastatic prostate cancer.

MATERIALS AND METHODS

A search was performed for 1990 to 2004 using the MEDLINE database, CancerLit database and reference lists of relevant studies to obtain articles addressing the use of serum PSA to follow patients after treatment for prostate cancer. Studies were reviewed to determine 1) if serial PSA monitoring provides an early and accurate surrogate assessment of cancer cure or treatment failure, 2) if any pattern in the PSA profile after treatment provides conclusive evidence of early local vs systemic failure, 3) the magnitude of the lead time to clinical failure that serial PSA monitoring may provide and 4) if the early identification of biochemical failure (BF) with earlier intervention improves outcome.

RESULTS

Although a lower PSA nadir after treatment with RT has been associated with cancer cure, 5% to 25% of patients ultimately have failure (beyond 5 years) even with the most optimal biochemical response. The most appropriate BF definitions to use after treatment for prostate cancer with RT remains controversial due to substantial differences in their accuracy, sensitivity, specificity and positive predictive value for clinical outcome. No pattern of PSA kinetics after treatment has conclusively been associated with a specific recurrence site. Biochemical failure definitions in patients treated with RT appear to provide a 6 to 18 month lead time to clinical failure but there are only limited published data to suggest that early intervention of any type (androgen deprivation, RT, surgery, etc) impacts survival.

CONCLUSIONS

The overall benefit of monitoring serum PSA after treatment for prostate cancer remains controversial. Considering the potential dangers associated with incorrectly assuming the efficacy of new forms of treatment, the toxicity of administering salvage therapies of uncertain efficacy after BF has been identified and the anxiety associated with tracking posttreatment serum PSA, additional studies must be done to determine the appropriate use of this marker in properly treating patients after therapy.

Undetectable prostate specific antigen at 6-12 months

BACKGROUND

The concept of a prostate-specific antigen (PSA) "nadir" has been used as a predictive marker for treatment success in patients treated with radiotherapy for localized prostate carcinoma. However, this approach is not applicable in patients who are concomitantly treated with short-term hormonal therapies. To address this, the authors sought to develop a new predictive marker in such patients after prostate brachytherapy (BT).

METHODS

Between March 1997 and November 2002, 194 men with clinical Stage T1A-T3N0M0 prostate carcinoma (according to the 1992 International Union Against Cancer/American Joint Committee on Cancer TNM classification system) were treated with interstitial palladium (103Pd3) BT and androgen ablation therapy with or without external beam radiotherapy (EBRT). Based on tumor characteristics, 127 patients received an antiandrogen, finasteride, and BT whereas 67 received an antiandrogen, leuprolide, and EBRT followed by a BT boost. Hormonal therapy was initiated 2-3 months before any radiotherapy for a total duration of 8-9 months. Follow-up included physical examination and determining the PSA level at 3-month intervals. Postoperative serum testosterone was evaluated in preoperatively potent patients with erectile dysfunction > 6 months after therapy. A PSA level < or = 0.06 ng/mL or < or = 0.20 ng/mL detected during a 6-12-month window after the implant were evaluated as predictors of biochemically disease-free survival (DFS), defined as the time to a PSA level > or = 1.0 ng/mL.

RESULTS

Of the 194 patients, 163 were available for analysis. The median length of follow-up was 48 months. In those patients with a PSA level < or = 0.20 ng/mL at 6-12 months, the DFS at 48 months after the implant was 96% (95% confidence interval [95% CI], 91-99%) compared with the remainder of the patients, whose DFS decreased to 80% (95% CI, 65-89%) (P < 0.001). When a PSA level < or = 0.06 ng/mL was used as an indicator, the 48-month DFS was 99% (95% CI, 91-100%) compared with that for patients with a PSA level > 0.06 ng/mL, in whom the DFS was 85% (95% CI, 74-92%) (P = 0.004). Furthermore, because testosterone levels may occasionally remain low after the cessation of luteinizing hormone-releasing hormone agonist therapy and result in erectile dysfunction and an artificially low PSA level, the authors reviewed the serum testosterone levels in 23 patients who were so treated and were experiencing erectile dysfunction. None had PSA values below the lower limit of normal.

CONCLUSIONS

A PSA level < or = 0.20 ng/mL or < or = 0.06 ng/mL measured at 6-12 months after BT appears to be a useful predictive marker for detecting early success in patients with prostate carcinoma who are treated with neoadjuvant androgen ablation and BT. These markers may be used to identify those patients who are at an increased risk of biochemical failure and may be useful in stratifying patients for closer follow-up, long-term adjuvant therapies, or clinical trials. A longer follow-up period will be needed to verify whether these are predictive of long-term cancer control.

Report of a multicenter Canadian phase III randomized trial of 3 months vs. 8 months neoadjuvant androgen deprivation before standard-dose radiotherapy for clinically localized prostate cancer

PURPOSE

To evaluate the effect of 3 months vs. 8 months of neoadjuvant hormonal therapy before conventional dose radiotherapy (RT) on disease-free survival using prostate-specific antigen PSA and biopsies as end points for clinically localized prostate cancer.

METHODS AND MATERIALS

Between February 1995 and June 2001, 378 men were randomized to either 3 or 8 months of flutamide and goserelin before conventional-dose RT (66 Gy) at four participating centers. The median patient age was 72 years (range, 50-84 years). The stage distribution was 17% T1c, 35% T2a, 34% T2b-T2c, 13% T3-T4. The Gleason score (GS) was < or =6 in 51%, 7 in 38%, and 8-10 in 11%. The median baseline PSA level was 9.7 ng/mL (range, 1.3-189 ng/mL). Of the 378 men, 26% were low risk (Stage T1c-T2a, GS < or =6, PSA <10 ng/mL), 43% were intermediate risk (Stage T2b or GS 7 or PSA 10-20 ng/mL), and 31% were high risk (Stage T3 or GS 8-10 or PSA >20 ng/mL). The two arms were balanced in terms of age, GS, T stage, risk group, and presenting PSA level. The median follow-up was 44 months (range, 10-84 months), and 361 patients were available for evaluation.

RESULTS

The 8-month arm achieved a lower PSA level before starting RT (0.37 vs. 0.74 ng/mL, p < or =0.001) and had a greater downsizing of the prostate (mean volume 26.6 cm(3) vs. 30.5 cm(3), p < or =0.001). However, the actuarial freedom from failure rate (biochemical by American Society for Therapeutic Radiology and Oncology definition, local or distant) for the 3-month vs. 8-month arms at 3 years was 66% vs. 68% and by 5 years was 61% vs. 62%, respectively (p = 0.36). No statistically significant difference was noted in the types of failure between the two arms (crude final status): biochemical, 22.2% vs. 22.3%; local, 10.2% vs. 6.5%; and distant, 3.4% vs. 4.4% (p = 0.61). Two-year post-RT biopsies were done in 57% (n = 205). Negative biopsies were obtained in 68% of the 3-month and 77% of the 8-month patients; 18% and 14% had indeterminate biopsies and 14% and 9% were positive for residual cancer (p = 0.34) in the two arms, respectively. The median PSA level for nonfailing patients was 0.50 ng/mL in both the 3-months and 8-month arms. A suggestion of improvement was found in the 8-month arm for disease-free survival at 5 years for high-risk patients (39% vs. 52%) but did not achieve statistical significance.

CONCLUSION

A longer period of neoadjuvant hormonal therapy before standard-dose RT does not appear to confer a benefit in terms of disease-free survival or to alter failure patterns. Failure was delayed in the 8-month arm, but this advantage was lost by 5 years of follow-up. A suggestion of benefit was noted with a longer period of hormonal therapy for high-risk patients.

Recurrent prostate cancer following external beam radiotherapy

All patients who undergo curative therapy for prostate cancer should be followed for a prolonged period of time to determine tumor control and treatment toxicity for quality assurance purposes. Follow-up duties may be reasonably shared between the oncologist and the family doctor or urologist: however, it is probable that some follow-up information specific to the irradiated patient will be lost unless the oncologist maintains regular contact with the patient, especially in the first 5 years of follow-up when late radiation effects are most likely to appear. There is no strong evidence that patients stop being at risk for recurrence at any time after treatment, and because PSA testing is an accurate, simple, and inexpensive method of determining post-RT tumor status, it is recommended that periodic PSA measurements be continued for life. In the absence of a rising PSA, all other tests and visits are unnecessary to determine post-RT tumor control. Because DRE has been shown to be of limited utility in follow-up of irradiated patients, it should be possible to effectively follow patients remotely. This could be done by asking patients to have PSA tests done, forward the results to their physicians, and report treatment toxicity when it occurs. Only abnormal results would trigger an office visit. This strategy is being evaluated in clinical trials. The alternative is to delegate the follow-up to the primary-care physician with guidelines as to when referral back is required. Follow-up frequency, and the most beneficial follow-up investigations vary from scenario to scenario, and are influenced by the likelihood of relapse, time to relapse, and planned intervention. These decisions are influenced in turn by the initial presentation--either with high or low risk factors--and by the patient's general state of health at completion of EBRT. Effective follow-up also requires active patient cooperation that only can be achieved after discussion of the goals of follow-up with the patient and with the patient's full understanding of the process. The follow-up strategy proposed in Fig. 1 is most suitable for a fit patient with low or intermediate risk factors who wishes to consider all salvage options should he relapse, or for the high-risk individual in situations in which the probability of systemic relapse is of major concern. Young patients with very adverse risk factors may benefit from even closer follow-up in the early years after EBRT and the elderly or frail may require only occasional visits to record or treat treatment toxicity and to ensure clinical non-progression.

Prostate biopsy status and PSA nadir level as early surrogates for treatment failure: analysis of a prostate cancer randomized radiation dose escalation trial

PURPOSE

A positive biopsy after external beam radiotherapy in patients free of any evidence of treatment failure is not synonymous with eventual recurrence. Although biopsy positivity is a predictor of outcome, the utility of biopsy status as a surrogate end point, the effect of radiation dose on biopsy status, and the interrelationships of these associations to prostate-specific antigen (PSA) nadir level are not well-defined. These issues were investigated in a cohort of men with Stage T1-T3 prostate cancer who were randomized to receive between 70 Gy and 78 Gy and were prospectively biopsied at about 2 years after the completion of radiotherapy (RT).

METHODS AND MATERIALS

Of the 301 assessable patients in the trial, 168 underwent planned sextant or greater prostate post-RT biopsies in the absence of biochemical or clinical failure; this group constituted the study cohort. Of the 168 patients, 87 were in the 70-Gy arm and 81 in the 78-Gy arm. Biopsies were classified into four groups: negative (no tumor), atypical/suspicious cells (not diagnostic of carcinoma), carcinoma with treatment effect (CaTxEffect), and carcinoma without treatment effect (CaNoTxEffect). Any diagnosis of carcinoma in the specimen was classified as biopsy positive. Freedom from failure (FFF) included biochemical failure and/or clinical failure. Kaplan-Meier curves were calculated from the completion of RT. For those alive in the study cohort, the median follow-up was 65 months.

RESULTS

The rate of biopsy without tumor was 42%; with atypical cells, it was 28%, with CaTxEffect 21%, and with CaNoTxEffect 9%. The overall biopsy positivity rate (CaTxEffect + CaNoTxEffect) was 30%; 28% in the 70-Gy group and 32% in the 78-Gy group (p = 0.52). The distribution of PSA nadir levels was 73% <or=0.5, 20% >0.5-1.0, 5% >1.0-2.0, and 1% >2.0 ng/mL. Significantly more patients randomized to 78 Gy had a PSA nadir of <or=0.5 ng/mL (80% vs. 67%; p = 0.02). No relationship was found between PSA nadir level and prostate biopsy status. The 5-year FFF rate for those classified as biopsy negative was 84% and for those biopsy positive was 60% (p = 0.0002). Radiation dose did not significantly alter FFF rates by prostate biopsy status. Nadir PSA level correlated with FFF, although this was dependent on the inclusion of the 2 patients with a PSA nadir >2.0 ng/mL.

CONCLUSION

For patients free of treatment failure at the time of prostate biopsy 2 years after RT, the prognosis of no tumor cells was the same as that of atypical/suspicious cells and CaTxEffect was the same as CaNoTxEffect. The biopsy positivity rate was not altered by dose, suggesting that most of the outcome differences between the 70-Gy and 78-Gy groups were due to events occurring before prostate biopsy at 2 years and/or were not entirely dependent on biopsy status. Biopsy status is a strong prognostic factor, but, as an early end point, it may be misleading. PSA nadir appears to have little clinical value in patients treated to doses of >/=70 Gy who are failure free 2 years after RT.

The use of conformal radiotherapy and the selection of radiation dose in T1 or T2 low or intermediate risk prostate cancer – a systematic review

BACKGROUND AND PURPOSE

The purpose was to develop a systematic review that would address the following questions: (a) when single-modality treatment external-beam radiotherapy is selected as the modality of choice, what is the role of three-dimensional (3D) conformal radiotherapy in treating clinically localized (T1, T2/NO, NX/MO) prostate cancer? The outcomes of interest are biochemical freedom from failure (bNED) rates, clinical recurrence-free survival, disease-specific survival and acute and late toxicity; (b) what is the appropriate dose and fractionation prescription in this clinical setting?

MATERIALS AND METHODS

A systematic review of the English published literature was undertaken to provide evidence relevant to the above outcomes.

RESULTS

One randomized controlled trial comparing conventional radiotherapy to conformal therapy with dose escalation reported bNED rates. Three additional randomized controlled trials reported acute or chronic late outcome assessments. Additionally, phase II studies of dose escalation in sequential patient cohorts and non-randomized comparative assessments of dose-response and bNED rates in controlled analyses were reviewed. There is convincing evidence from randomized trials that the use of conformal therapy reduces acute and late treatment-related morbidity. There is preliminary evidence suggesting that when external-beam therapy alone is used to treat patients, conformal therapy with dose-escalation is more efficacious than doses of 70Gy. The increased efficacy appears to be predominantly seen in the subset of patients with intermediate-risk disease (PSA 10-20). There is conflicting evidence of the efficacy of dose-escalation in patients with low initial PSA (<10) and in patients with initial PSA greater than 20. Conformal radiotherapy at a dose of 78Gy appears to be relatively safe with no increase in acute or late effects compared with conventional treatment (up to 70Gy) so long as appropriate technological principles are considered.

CONCLUSIONS

Patients who have external-beam radiotherapy should be treated using a 3D conformal technique. Patients with intermediate-risk disease (PSA 10-20) who are treated with external-beam radiotherapy alone should be offered doses of 75-78Gy in 180-200cGy fractions.

Intensity-modulated radiation therapy for prostate cancer

Intensity-modulated radiation therapy (IMRT) represents a new paradigm in radiation treatment planning and delivery for treatment of prostate cancer with enormous potential. Preliminary data indicate that this highly conformal treatment technique can effectively reduce acute and late-occurring toxicities, improving the quality of life of the treated patient and serving as the optimal dose escalation tool. IMRT produces radiation distributions capable of delivering different dose prescriptions to multiple target sites, providing a new opportunity for differential dose painting to increase the dose selectively to specific, image-defined regions within the prostate. Clinical trials will be necessary to define more clearly the true extent of improved tumor control and reduction in normal tissue complications with IMRT in the treatment of prostate cancer.

[Clinical and biological surveillance after radiotherapy for localized prostate cancer]

Serum PSA is an excellent marker of disease status after external beam radiotherapy or brachytherapy for patients with prostate carcinoma. A low PSA nadir < or = 1 even < or = 0.5 ng/mL has been shown to be as a surrogate end point for disease control. Three successive increases of this marker after achieving the nadir defines recurrence as recommended by the American Society for Therapeutic Radiology and Oncology. The biochemical relapse or PSA failure after treatment precedes clinical disease relapse by several months. PSA profile or kinetics may have implications for patterns of failure and prognosis. Prostate post-radiotherapy biopsies should not be part of routine follow-up as its interpretation is frequently problematic. Other exams should not be performed unless clinical symptoms are present. Post-radiotherapy relapse treatment has generally no curative intent.

Intensity-modulated radiotherapy

Intensity-modulated radiotherapy represents a recent advancement in conformal radiotherapy. It employs specialized computer-driven technology to generate dose distributions that conform to tumor targets with extremely high precision. Treatment planning is based on inverse planning algorithms and iterative computer-driven optimization to generate treatment fields with varying intensities across the beam section. Combinations of intensity-modulated fields produce custom-tailored conformal dose distributions around the tumor, with steep dose gradients at the transition to adjacent normal tissues. Thus far, data have demonstrated improved precision of tumor targeting in carcinomas of the prostate, head and neck, thyroid, breast, and lung, as well as in gynecologic, brain, and paraspinal tumors and soft tissue sarcomas. In prostate cancer, intensity-modulated radiotherapy has resulted in reduced rectal toxicity and has permitted tumor dose escalation to previously unattainable levels. This experience indicates that intensity-modulated radiotherapy represents a significant advancement in the ability to deliver the high radiation doses that appear to be required to improve the local cure of several types of tumors. The integration of new methods of biologically based imaging into treatment planning is being explored to identify tumor foci with phenotypic expressions of radiation resistance, which would likely require high-dose treatments. Intensity-modulated radiotherapy provides an approach for differential dose painting to selectively increase the dose to specific tumor-bearing regions. The implementation of biologic evaluation of tumor sensitivity, in addition to methods that improve target delineation and dose delivery, represents a new dimension in intensity-modulated radiotherapy research.

Health-related quality of life in patients with screen-detected versus clinically diagnosed prostate cancer preceding primary treatment

BACKGROUND

The purpose of this study was to evaluate baseline health-related quality of life (HRQOL) in patients with localized prostate cancer before primary treatment (radical prostatectomy or radiotherapy).

METHODS

Two hundred patients with newly diagnosed localized (screen-detected or clinically diagnosed) prostate cancer completed HRQOL questionnaires (generic and disease-specific measures). Clinical data were collected from patients' medical records in four Rotterdam hospitals.

RESULTS

Screen-detected tumors were of more favorable stages and grades than clinically diagnosed ones. The diagnostic groups did not differ significantly in bowel and sexual functioning. Differences were found in urinary functioning, favoring patients with screen-detected tumors of T2-T3 stages. Patients with screen-detected T2 cancer reported better generic HRQOL (physical aspects) than the clinical group, but HRQOL of the latter group was similar to the population norm. Radiotherapy patients were significantly older and had more comorbidity than subjects referred to prostatectomy. Urinary, bowel, and sexual problems were uncommon. Older (> 65 years) radiotherapy patients appeared to be less sexually active. Radiotherapy patients also reported poorer levels of generic HRQOL.

CONCLUSIONS

Screen-detected prostate cancer patients presented with more favorable cancer stage and grade. HRQOL was related to both the tumor stage and the detection method. Pre-treatment HRQOL differences between prostatectomy and radiotherapy patients were associated neither with tumor characteristics nor with the detection method. Baseline differences in HRQOL should be taken into account when evaluating post-treatment HRQOL.

Equivalent racial outcome after conformal radiotherapy for prostate cancer: a single departmental experience

PURPOSE

African-American (AA) men with prostate cancer present with advanced disease, relative to white (W) men. This report summarizes our clinical and biochemical control (bNED) rates after conformal radiotherapy (RT). In particular, we aim to characterize any race-based outcome differences seen after comparable treatment.

PATIENTS AND METHODS

We reviewed 893 patients (418 AA and 475 W) with clinically localized prostate cancer treated between 1988 and 1997. Neoadjuvant hormonal blockade was used in 22.5% of cases, and all patients received conformal RT to a median dose of 68 Gy (range, 60 to 74.8 Gy). Biochemical failure was defined according to the American Society of Therapeutic Radiology and Oncology consensus definition. Median follow-up was 24 months (range, 1 to 114 months).

RESULTS

The 5-year actuarial survival, disease-free survival, and bNED rates for the entire population were 80.5%, 70.0%, and 57.6%, respectively. When classified by prognostic risk category, the 5-year actuarial bNED rates were 78.7% for favorable, 57.7% for intermediate, and 39.8% for unfavorable category patients. AA men presented at younger ages and with more advanced disease. Controlled for prognostic risk category, AA and W men had similar 5-year actuarial bNED rates in favorable (78% v 79%, P: = .91), intermediate (52% v 62%, P: =.44), and unfavorable categories (36% v 45%, P: = .09). Race was not an independent prognostic factor (P: = .36).

CONCLUSION

Conformal RT is equally effective for AA and W patients. More research is needed in order to understand and correct the advanced presentations in AA men. These data suggest a need for early screening in AA populations.

Matched-pair analysis of conformal high-dose-rate brachytherapy boost versus external-beam radiation therapy alone for locally advanced prostate cancer

PURPOSE

We performed a matched-pair analysis to compare our institution's experience in treating locally advanced prostate cancer with external-beam radiation therapy (EBRT) alone to EBRT in combination with conformal interstitial high-dose-rate (HDR) brachytherapy boosts (EBRT + HDR).

MATERIALS AND METHODS

From 1991 to 1998, 161 patients with locally advanced prostate cancer were prospectively treated with EBRT + HDR at William Beaumont Hospital, Royal Oak, Michigan. Patients with any of the following characteristics were eligible for study entry: pretreatment prostate-specific antigen (PSA) level of >/= 10.0 ng/mL, Gleason score >/= 7, or clinical stage T2b to T3c. Pelvic EBRT (46.0 Gy) was supplemented with three (1991 through 1995) or two (1995 through 1998) ultrasound-guided transperineal interstitial iridium-192 HDR implants. The brachytherapy dose was escalated from 5.50 to 10.50 Gy per implant. Each of the 161 EBRT + HDR patients was randomly matched with a unique EBRT-alone patient. Patients were matched according to PSA level, Gleason score, T stage, and follow-up duration. The median PSA follow-up was 2.5 years for both EBRT + HDR and EBRT alone.

RESULTS

EBRT + HDR patients demonstrated significantly lower PSA nadir levels (median, 0.4 ng/mL) compared with those receiving EBRT alone (median, 1.1 ng/mL). The 5-year biochemical control rates for EBRT + HDR versus EBRT-alone patients were 67% versus 44%, respectively (P <.001). On multivariate analyses, pretreatment PSA, Gleason score, T stage, and the use of EBRT alone were significantly associated with biochemical failure. Those patients in both treatment groups who experienced biochemical failure had a lower 5-year cause-specific survival rate than patients who were biochemically controlled (84% v 100%; P <.001).

CONCLUSION

Locally advanced prostate cancer patients treated with EBRT + HDR demonstrate improved biochemical control compared with those who are treated with conventional doses of EBRT alone.

The correlation of serial prostate specific antigen measurements with clinical outcome after external beam radiation therapy of patients for prostate carcinoma

BACKGROUND

The authors analyzed retrospectively their institution's experience in treating patients with localized prostate carcinoma with external beam radiation therapy (EBRT) to determine the correlation of various biochemical failure (BF) definitions with clinical failure and cause specific survival (CSS).

METHODS

Between January 1987 and December 1997, 1,094 patients with clinical T1-T3N0M0 prostate carcinoma were treated with definitive EBRT alone at William Beaumont Hospital, Royal Oak, Michigan. All patients received EBRT alone (no adjuvant hormones) to a median total prostate dose of 66.6 grays (Gy) (range, 59.4-70.4 Gy). Multiple BF definitions were tested for their correlation with clinical failure and cause specific death (CSD = 1-CSS). All BF definitions were tested for sensitivity, specificity, and accuracy of predicting subsequent clinical failure and CSD. Positive and negative predictive values were calculated in the form of 10-year actuarial clinical failure and CSD rates. Analyses were performed on all 1,094 patients as well as for those 727 patients who had at least 5 post-RT prostate specific antigen (PSA) level measurements and who did not receive hormonal therapy for post-RT PSA elevations. The median PSA follow-up was 4.0 years for the entire population and 4.5 years for those 727 patients included in the second analysis.

RESULTS

In the entire population, 167 patients (15%) experienced clinical failure corresponding to 5- and 10-year actuarial rates of 16% and 34%, respectively. The correlation of various BF definitions with outcome was calculated in those 727 patients who did not receive hormonal therapy. For these patients, BF (as defined by the American Society for Therapeutic Radiology and Oncology Consensus Panel) yielded a 73% sensitivity, 76% specificity, and 75% overall accuracy for predicting clinical failure and a 74% sensitivity, 69% specificity, and 69% overall accuracy for predicting CSD. The 10-year clinical failure rate for those 251 patients demonstrating 3 consecutive PSA rises (BF) was 64% versus 14% for those patients who did not meet these criteria (biochemically controlled [BC]). As expected, definitions requiring only two rises were more sensitive but less specific in predicting clinical failure than those definitions requiring three or four rises. Because there were dramatically more clinically controlled patients (85%) than clinical failures (15%), the overall accuracy for each definition more closely approximated its specificity. The definitions classifying BF as a postnadir increase of > or = 3 or > or = 4 ng/mL above the nadir yielded the highest accuracies of 87% and 88%, respectively. In addition, these definitions also appeared to provide the greatest separation in clinical failure rates between BC and BF patients, an absolute difference of 77% and 76%, respectively.

CONCLUSIONS

The correlation between BF and clinical failure and CSD varies markedly depending on the BF definition used. Definitions incorporating a fixed baseline (the nadir level) and the postnadir PSA profile may have better correlation with clinical failure than definitions using the nadir only or a specific number of consecutive rises in which a variable baseline "resets" after a PSA decrease.

Feasibility study combining low dose rate (192)Ir brachytherapy and external beam radiotherapy aiming at delivering 80-85 Gy to prostatic adenocarcinoma

BACKGROUND

Increasing the radiation dose to prostatic adenocarcinoma has provided higher local control rates. A total of 80 Gy seem necessary to achieve this goal but patient set-up and prostate motion remain difficult problems to solve in conformal radiotherapy. Brachytherapy which overcomes these points could be an alternative way to external beam boost fields. We wanted to transpose the irradiation models largely used in cervix cancer treatment combining external beam radiotherapy and low dose rate brachytherapy.

MATERIALS AND METHODS

In 71 patients with 19.5 and 13 ng/ml mean and median PSA levels, respectively, a dose escalation from 74 to 85 Gy was performed in four groups.

RESULTS

Shifting from intraoperative placement of sources vectors (Group I) to positioning under ultrasound controls (groups II-IV), improving the implantation shape and optimizing radiation delivery to urethral bed have reduced the total dose to rectal wall under 65 Gy and to urethra under 100 Gy. Rectal/prostate dose ratio was lowered from 0.7 (Groups I-II) to 0.58 (Groups III-IV) while avoiding problems resulting from pelvic bone arch interference, prostate volume or seminal vesicles location. The mean and median follow-up periods are 28 and 18 months. In Groups III and IV 85% of patients without hormonotherapy treated with 80-85 Gy normalized PSA under 1 ng/ml within 6 months. No severe late effect has been noted for patients implanted under echographic control.

CONCLUSIONS

The method described allows to deliver 85 Gy. Longer follow-up is however needed but the levels of dose delivered are not expected to induce prohibitive side effects.

Post-treatment PSA < or = 0.2 ng/mL defines disease freedom after radiotherapy for prostate cancer using modern techniques

OBJECTIVES

The prostate-specific antigen (PSA) definition of disease freedom after radiotherapy for prostate cancer is still in dispute. This report focuses on the PSA nadir achieved in men treated by modern radiotherapy techniques.

METHODS

From 1984 to 1994, 489 consecutive men with clinical Stage T1 -T2 prostate cancer were treated by simultaneous radiation: prostate iodine-125 implant followed by external beam radiation. A transperineal implant was performed on 143 men with Stage T1-T2NX, the focus of this study; 346 men with Stage T1-T2N0 had a retropubic implant. The median pretreatment PSA was 8.3 ng/mL (range 0.3 to 188). A rising PSA was defined as one that rose on three consecutive occasions above whatever nadir was achieved. A minimum 5-year follow-up (range 5 to 15) was reached by 453 men.

RESULTS

After a minimum 5-year follow-up, 336 men had a nonrising PSA, and of this group, 107 had undergone simultaneous radiation by the transperineal implant technique. A PSA nadir of 0.2 ng/mL or less was achieved by 97% of the transperineally implanted men, and 3% had a nadir of 0.3 to 1.0 ng/mL. Of the 489 men, those who had a nadir of 0.2 ng/mL or less had a 92% nonrising PSA rate (P = 0.001) 10 years after treatment compared with a 41% rate for men who had a nadir of 0.3 to 1.0 ng/mL. All men whose nadir was greater than 1.0 ng/mL had recurrence. The median time to achieve the PSA nadir of 0.2 ng/mL was 27 months (range 3 to 102).

CONCLUSIONS

Primarily on the basis of the results from men treated with simultaneous radiation using the transperineal technique, the definition of disease freedom for radiotherapy should be men who achieve and maintain a PSA nadir of 0.2 ng/mL or less.

Defining biochemical cure for prostate carcinoma patients treated with external beam radiation therapy

BACKGROUND

The authors retrospectively reviewed their institution's long term experience with conventional external beam radiation therapy (RT) for localized prostate carcinoma to identify criteria associated with long term biochemical cure.

METHODS

Between January 1987 and December 1994, 871 patients were treated with external beam RT alone for clinically localized prostate carcinoma at William Beaumont Hospital, Royal Oak, Michigan. All patients received only external beam RT to a median total dose of 66.6 grays (Gy) (range, 59.4-70.4 Gy). No patient received hormonal therapy unless treatment failure was documented. The median follow-up was 5.0 years (range, 0. 2-11.8 years). Biochemical failure was defined according to the American Society for Therapeutic Radiology and Oncology Consensus Panel definition.

RESULTS

In the entire study group, 380 patients experienced biochemical failure at a median interval of 1.5 years after the completion of RT. The 5-year and 7-year actuarial rates of biochemical control were 50% and 48%, respectively. On multivariate analysis, a higher pretreatment prostate specific antigen (PSA) level, higher Gleason score, higher clinical T classification, higher nadir level, and shorter time interval to nadir all were associated significantly with biochemical failure (P < 0.001). The median intervals to biochemical failure for patients with pretreatment PSA levels </= 3.9 ng/mL, 4.0-19.9 ng/mL, and >/= 20.0 ng/mL were 2.2 years, 1.5 years, and 1.2 years, respectively (P < 0. 001). The median intervals to biochemical failure for patients with Gleason scores of 2-4, 5-7, and 8-10 were 1.8 years, 1.5 years, and 1.1 years, respectively (P < 0.001). Only 6 patients failed beyond 5 years after treatment even though 136 patients were at risk for failure beyond this point. When restricting analysis to 643 patients (74%) with >/= 3 years of PSA follow-up, the median nadir level for biochemically controlled patients was 0.6 ng/mL and occurred at a median interval of 1.9 years after RT versus a median nadir level of 1.3 ng/mL (P = 0.002) occurring at a median interval of 1.0 years (P < 0.001) in those patients who experienced biochemical failure. Patients were divided into subgroups based on their PSA nadir level and time to nadir. The 5-year actuarial biochemical control rates for patients with nadir values of </= 0.4 ng/mL, 0.5-0.9 ng/mL, 1. 0-1.9 ng/mL, 2.0-3.9 ng/mL, and >/= 4.0 ng/mL were 78%, 60%, 50%, 20%, and 9%, respectively (P < 0.001). The 5-year actuarial biochemical control rates for patients who reached their nadir at < 1.0 years, 1.0-1.9 years, 2.0-2.9 years, and >/= 3.0 years were 30%, 52%, 64%, and 92%, respectively (P < 0.001). All 52 patients who achieved a nadir of </= 0.4 ng/mL and required >/= 2.0 years to reach this nadir had biochemically controlled disease.

CONCLUSIONS

These results suggest that a patient has a high likelihood of biochemical cure after treatment for prostate carcinoma with conventional doses of external beam RT if he has not demonstrated biochemical failure within 5 years of treatment. Patients with lower pretreatment PSA levels and lower Gleason scores may require longer follow-up than those with less favorable characteristics to achieve the same certainty of cure. Patients who achieve a PSA nadir </= 0.4 ng/mL and require >/= 2.0 years to reach this nadir have the highest probability of cure.

The importance of adequate follow-up in defining treatment success after external beam irradiation for prostate cancer

PURPOSE

We reviewed our institution's experience treating patients with localized prostate cancer with external beam radiation therapy (RT) to determine how differences in the length of follow-up affect the determination of treatment outcome using the American Society for Therapeutic Radiology and Oncology (ASTRO) Consensus Panel Definition of biochemical failure (BF).

METHODS AND MATERIALS

From January 1987 through December 1997, 1109 patients with localized prostate cancer were treated with definitive external beam RT at William Beaumont Hospital, Royal Oak, Michigan. All patients received external beam RT to a median total prostate dose of 66.6 Gy (range: 59.4-70.4 Gy). A total of 1096 patients (99%) had sufficient prostate-specific antigen (PSA) follow-up to determine their biochemical status. To test the impact of differences in follow-up on the calculation of BF, 389 patients with at least 5 years of PSA follow-up were selected as the reference group for the initial analysis. BF was then retrospectively determined using the Consensus Panel definition at yearly intervals, ignoring the remainder of each patient's follow-up. The median follow-up for this group of patients was 6.6 years (range: 5.0-11.6 years). In a second analysis, patient cohorts were randomly selected with varying median PSA follow-up intervals in order to more accurately represent a population whose follow-up is distributed continuously over a defined range. Seven cohorts were randomly selected with 200 patients in each cohort. Cohorts were individually identified such that half of the patients (100) had 2 years or less follow-up than the stated time point for analysis and half (100) had up to 2 years more follow-up than the time point chosen for analysis. For example, in the cohort with a median follow-up of 3 years, 100 patients with a PSA follow-up from 1 to 3 years were randomly selected, and 100 patients with a follow-up from 3 to 5 years were randomly selected, thus generating a median follow-up of 3 years for this cohort (range: 1 to 5 years). This process was repeated five times for five random samples of seven cohorts each. Biochemical failure was calculated according to the Consensus Panel definition.

RESULTS

In the first analysis, significantly different rates of biochemical control (varying by 6-21%) were calculated for the same actuarial year chosen for analysis depending only upon the length of follow-up used. For example, the 3-year actuarial rate of biochemical control (BC) varied from 71% when calculated with 3 years of follow-up versus 50.4% with 7 years (p < 0.01). These differences in actuarial rates of BC were observed in all subsets of patients analyzed (e.g., PSA < 10, Gleason < or = 6, n = 132,p < 0.001; PSA < 10, Gleason > or = 7, n = 33, p = 0.03; PSA > or = 10, Gleason < or = 6, n = 109, p < 0.001; and PSA > or = 10, Gleason > or = 7, n = 72, p = 0.002). The absolute magnitude of the difference in actuarial rates of BC was greatest during years 2 (range 18-30%), 3 (range 16-25%), and 4 (range 15-24%) after treatment. In the second analysis using median PSA follow-ups (as defined above), statistically significant differences in actuarial rates of BC were again observed. For example, the 3-year actuarial rate of BC varied from 74.8% with a median follow-up of 2 years versus 49.2% with a median follow-up of 6 years. These dramatic differences in BC were still observed beyond 5 years.

CONCLUSION

When the ASTRO Consensus Panel definition of BF is used to calculate treatment success with external beam RT for prostate cancer, adequate follow-up is critical. Depending upon the length of time after treatment, significantly different rates of BC (varying by 15% to 30%) can be calculated for the same time interval chosen for analysis. These results suggest that data should only be reported if the length of follow-up extends at least beyond the time point at which actuarial results are examined for the majority of patients.

Conformal proton therapy for early-stage prostate cancer

OBJECTIVES

To assess the effect of proton radiation on clinical and biochemical outcomes for early prostate cancer.

METHODS

Three hundred nineteen patients with T1-T2b prostate cancer and initial prostate-specific antigen (PSA) levels 15.0 ng/mL or less received conformal radiation doses of 74 to 75 cobalt gray equivalent with protons alone or combined with photons. No patient had pre- or post-treatment hormonal therapy until disease progression was documented. Patients were evaluated for biochemical disease-free survival, PSA nadir, and toxicity; the mean and median follow-up period was 43 months.

RESULTS

Overall 5-year clinical and biochemical disease-free survival rates were 97% and 88%, respectively. Initial PSA level, stage, and post-treatment PSA nadir were independent prognostic variables for biochemical disease-free survival: a PSA nadir 0.5 ng/mL or less was associated with a 5-year biochemical disease-free survival rate of 98%, versus 88% and 42% for nadirs 0.51 to 1.0 and greater than 1.0 ng/mL, respectively. No severe treatment-related morbidity was seen.

CONCLUSIONS

It appears that patients treated with conformal protons have 5-year biochemical disease-free survival rates comparable to those who undergo radical prostatectomy, and display no significant toxicity. A Phase III randomized dose-escalation trial is underway to define the optimum radiation dose for early-stage prostate cancer.

The management of PSA failure after radical radiotherapy for localized prostate cancer

An asymptomatic rising serum prostate-specific antigen (PSA) level is the most common form of failure after radical radiotherapy for localized prostate cancer, but there is no consensus as to how it should be managed. This review addresses the following three questions concerning men with PSA failure after radiotherapy: (i) what is the course of the disease without further intervention?; (ii) what is the role of radical treatment, such as salvage prostatectomy?; and (iii) should androgen deprivation be started immediately or should it be delayed until clinical progression occurs? An algorithm for the management of PSA failure after radical radiotherapy for localized prostate cancer is proposed.